<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="vue.js"></script>
</head>

<body>
    <div id="app">
        <button v-on:click="jjj">-</button><span>{{num}}</span><button v-on:click="ccc">+</button>
    </div>
    <script>
        var app = new Vue({
            el: "#app",
            data: {
                count: 0,
                num:"00",
                // isk:null
            },
            methods: {
                jjj: function () {
                    this.count--;
                  if(this.count<0){
                    this.count=0;
                    this.num="00";
                    alert("最小值了")
                    // this.isk="disabled";--
                  }
                  if(this.count>=10){
                        this.num=this.count;
                    }else{
                        this.num="0"+this.count;
                    }
                },
                ccc: function () {
                    this.count++;
                    if(this.count>=10){
                        this.num=this.count;
                    }else{
                        this.num="0"+this.count;
                    }
                }
            },
        })
    </script>
</body>

</html>